The hypothesis of the LIFE trial is (active enrollment phase is completed--only patient followup is continuing) that, compared to atenolol, losartan will reduce the incidence of cardiovascular (CV) morbidity and mortality in patients with essential hypertension and left ventricular hypertrophy (LVH) by 15%. The primary endpoint is the combined incidence of CV morbidity and mortality. The primary objective is to evaluate the long-term effects (+/>4 years) of losartan compared to atenolol in hypertensive patients with documented LVH on the combination of CV morbidity and mortality (CV mortality defined as death due to fatal myocardial infarction [MI], fatal stroke, sudden death, death resulting from progressive heart failure and other CV deaths; CV morbidity defined as nonfatal MI [excluding silent MI]and nonfatal stroke). The LIFE Study includes the following substudies: QUALITY OF LIFE (Substudy ID No. 133-03)--The purpose of this substudy is to assess differences in quality of life among patients with hypertension and LVH who are treated with losartan versus atenolol at 1, 2, 6 and 12 months of therapy. This substudy examines the treatment-related influences, as defined by patient responses on the health-related domain (psychological well-being) score for vitality ( a subdomain under psychological well-being) and the symptom inventory item relating to tiredness/fatigue. These responses are recorded on a self-administered quality of like (QoL) questionnaire which has been specifically designed for hypertensive clinical studies. This questionnaire is a battery of scales utilizing groups of existing, validated QoL instruments. AFRICAN AMERICAN ECHO-SUBSTUDY FOR LIFE TRIAL (Substudy ID No. 133-05)--The LIFE trial is to conduct an echocardiographic substudy in 12% of the study population in each country. Approximately 360 African Americans will be followed in the U.S. (goal for total U.S. patients is 3,000). The presence of LVH by ECG (Cornell criteria) is a major inclusion criteria for the main LIFE trial, and the comparison of LVH regression by ECG is listed as a study objective. However, several studies have documented that the assessment of LVH by ECG in Blacks is significantly less accurate than in other ethnic populations. The diagnosis of LVH by echocardiogram was similar in Black and White populations. The LIFE trial uses a supposedly more accurate modification of the Cornell criteria (QRS voltage duration product) for LVH assessment; however, this method has not been adequately evaluated in significant numbers of Black hypertensives. This will clearly create problems in extrapolating the results of the LIFE trial to a major population of hypertensives. The reasons for the difference in accuracy of the ECG in identifying LVH in Black vs White populations are unknown and, since the accurate assessment of LVH risk is essential for the Trial, it is essential for the LIFE trial that it is utilizing the best method for determining the presence of LVH in all populations. Thus, LIFE included an echocardiographic substudy to determine the correlation of LVH by the LIFE Trial ECG criteria and other methods with echocardiographically diagnosed LVH. If the desired composition of the U.S. study population of 10-15% (~360) African Americans is achieved and this demographic profile is carried over into the "LIFE Trial Echocardiographic Substudy" sample, only 35-50 Black subjects will be studied. This is an insufficient number of Blacks to validate the ECG findings in Blacks in the full study. Thus, the "AFRICAN AMERICAN Echo-Substudy for the LIFE Trial" oversampled Blacks in the LIFE Trial and Echocardiographic Substudy; this cohort will be followed using both the LIFE Trial ECG criteria and echocardiography to confirm the validity of the LIFE Trial results in Black hypertensives. Specifically, the specificity of the LIFE Trial ECG criteria in the detection of echocardiographically confirmed LVH in the Trial's Black participants will be assessed.